El Trompito Taqueria is a smashing wonderland of Mexican street food dominated by the thud of cleavers in the open kitchen, where workers assemble tacos, huaraches, alambres, skyscraping tortas and aguas frescas made with fresh fruit. But the taqueria's essential dish is the mixiote de borrego, an overnight-braised lamb shank. The shards and slivers of meat, at once crunchy and soft, are heavy with a pungent, in-your-throat musk; they're swathed in a chile-slapped adobo sauce studded with prickly-pear cactus leaves. The lamb arrives with a heap of corn tortillas, Mexican rice and refritos dotted with crumbles of queso fresco; you can accessorize your meal from the salsa bar that squats in the middle of the festive, lively dining room.